3.2 has no syntax highlighting in code blocks for any language. My recommendation is to use a JavaScript highlighter such as highlight.js or SyntaxHighlighter. My preference goes to highlight.js because it automatically detects the language of the source and it also requires one script tag to be installed. Both are available on various CDNs.

Not really, I forked the repo in order to play with it and I haven't till now developped an extension for phpBB which uses it. To add, what stopped me to go ahead here has been the fact I read that's not so accurate with the PHP code.

We went to codemirror due to its power, as an example here's the rendered PHP with lines.
A grab from our extension's environment, in the future I will see to extract the code in order to make a separated extension from it.
.